1. Field of the Invention
The present invention relates to a method and system of diagnosing a breakdown of a component during a pre-charging operation, and more particularly to a method and system of diagnosing a breakdown of a component during a pre-charging operation, which diagnose a breakdown of a component from a voltage and a current of a battery detected during the pre-charging operation and a voltage applied to a capacitor of an inverter during the pre-charging operation.
2. Description of the Related Art
Hybrid vehicles and electric vehicles are vehicles which obtain force (e.g., driving power) for driving wheels by rotating a motor with use of electricity from a high voltage battery. A Power Relay Assembly (PRA) includes a main relay and a pre-charging circuit. The main relay is switched on and off to allow current to be applied to an inverter from a high voltage battery, thereby rotating a motor. A pre-charging circuit causes the capacitor of the inverter to be pre-charged before the high voltage battery and the capacitor of the inverter are connected via the main relay. This pre-charging operation prevents arc discharge which may occur when the high voltage battery and the capacitor of the inverter are directly connected to each other without an intervening main relay, thereby securing stability of a circuit.
During the pre-charging operation, an output voltage of the high voltage battery and a voltage of the capacitor of the inverter are compared with each other, a predetermined time, for example, about 20 ms after starting of the pre-charging operation. When the voltage applied to the capacitor of the inverter is about 80% of the output voltage of the high voltage battery or greater, it is determined to be normal (e.g., no failure), but it is, otherwise, determined to be abnormal, i.e., determined that a breakdown of a component has occurred.
In response to determining an abnormal condition during the pre-charging operation, the PRA is replaced, a battery management system (BMS) which operates the high voltage battery is replaced, and other component are checked to see when they are normal or broken down (e.g., failure has occurred). In other words, all components sequentially undergo an inspection process. On the other hand, when a component is out of order while the pre-charging operation is performed, a pre-charging a resistor may be burned, and operation of preventing an engine from being started is performed.
The foregoing is intended merely to aid in the understanding of the background of the present invention, and is not intended to mean that the present invention falls within the purview of the related art that is already known to those skilled in the art.